The tagline for Death Force a.k.a. Fighting Mad a.k.a. Vengeance is Mine is She's in Playboy. He's out of the penitentiary. Together they are fighting mad! Doug ('cause all heroes should be named Doug) is left for dead by smugglers and saved by Japanese soldiers and taught the ways of the samurai. Then revenge happens.
trailer - https://www.youtube.com/watch?v=yU_dgQ0pVdg
full movie - https://www.youtube.com/watch?v=pL-rHJicLSo